Mechaniscally-operating retarding device for projectile fuses and other firing devices



Jan. 15, 1929.

1, 99,336 L. E. REMONDY. MECHANICALLY OPERATING RETARDING DEVICE FOR PROJECTILE FUSES AND OTHER FIRING DEVICES I Filed May 17, 1926 7 Sheets-Sheet 1 o my] G g D D E j III- H Jan. i5, v

L. E. REMONDY MECHANICALLY OPERATING RETARDING DEVICE FOR PRQJECTILE FUSES AND OTHER FIRING DEVICES Filed May 17, 1926 '7 sneets-sn m 2 Jan. '15, 1929. J 1,699,336

L. E. REMONDY LLY OPERATING RETARDING DEVI FOR MECHANICA PROJECTILE FUSES AND OTHER FIRING D 03s A Filed May 17, 1926 7 Sheets-Sheet- 3 L. E. REMONDY MECHANICALLY OPERATING. RETARDING DEVICE FOR PROJECTILE FUSES AND OTHER FIRING DEVICES Filed'May 17, 1926 '7 Sheets-Sheet 4 Jan. 15, 1929.

L. E. REMONDY MEGHANICALLY OPERATING RETARDING DE cs FOR I PROJECTILE FUSES AND BR FIRING ICES Filed May 1926 7 Sheets-Sheet 5 E y I 4- lV/l/ 1,699,336 E. REMONDY Filed llay 17, 1926 '7 Sheets-Sheet '6 A i W Jan. 15, 1929.

MECHANICALLY OPERATING RETARDING DEVICE FOR PROJECTILE FUSES AND OTHER FIRING DEVICES Jan. 15,1929. 1,699,336

. L. E. REMONDY E MEGHANICALLY OPERATING RETARDING VICE FOR PROJECTILE FUSES AND OTHER FIRI DEVICES 7 Sheets-Sheet '7 Fileq llay 17, 19 26 Till Patented Jan. 15, 1929.

Lnon EMILE nnmonnv, on PARIS, FRANGE.

MEGHANICALLY-OPERATING RETARDING DEVICE FOR PROJECTILE FUSES AND OTHER FIRING DEVICES.

Application filed May 17, 1926, Serial No. 109,768, and in France Jilly 11, 1925.

It is known that projectile fuses all comprise a firing mechanism having a striker and a percussion cap, one member at least of which is movable, firing or ignition resulting from the impact between these two members. The impact between the striker and the percussion cap must be capable of being retarded and even, in certain cases, being prevented from taking place in order to avoid any premature or untimely operation, or else in order that the operation can only take place at the end of a predetermined duration of flight. It may also be desired to render any operation impossible beyond a predetermined distance travelled by the projectile.

Further, the firing of the charge of the projectile must be capable in certain cases of being retarded, that is to say capable of being arranged so that it does not immediately follow the ignition of the percussion cap. In order to retard the firing of the charge after the ignition of the percussion cap use is most usually made of pyrotechnical devices. In order to safeguard against prematureor untimely operations use is most generally made of mechanical devices combined if desired with pyrotechnical devices.

The present invention relates to a mechanically operating retarding or nullifying device, more particularly adapted. for use with projectile fuses. The new device is essentially characterised by a crown of balls which may if desired be placed in a cage and which are placed between two convergent bearing surfaces one at least of which is formed upon the member to be displaced, such as a striker or a percussion cap, for example. One of the bearing surfaces for the balls is, in any *ase, provided upon a member adapted to make a movement of rotation under the effect of the action of the air, for example. The halls form wedges between their bearing surfaces, being driven between these surfaces by their own weight which may be increased by an additional rigid or elastic load.

The member to be displaced, thus wedged or locked by the balls can only advance by means of a helical movement of very small pitch. resulting from the combined rotation and advancing movement of the halls between their bearing surfaces, which forward movement of the balls cannot itself take place without a longitudinal push combined with the movement of rotation of at least one of the bearing surfaces.

The invention further comprises a series of additional safety devices which maybe employed in' combination with the ball retarding device or any other screw action retardin device.

Various practical examples of utilization and construction of the invention are illustrated in the accompanying drawings, in which:

Figure 1 shows in longitudinal sectional elevation the use of the invention for retarding the operation of the firing mechanism of a percussion fuse.v

Fig. 2 is a sectional view illustrating the mechanism, shown in Fig. 1, in firing posi-' tlon;

Figs. 3 and 4 are sectional views illustrating' a second embodiment of the present invention, the parts bein shown in their normal position and in ring poston, respectively Figs. 5, 6 and 7 are longitudinal sectional views illustrating another embodiment of the present invention;

Figs. 8, 9 and 10 illustrate, in longitudinal sectional views, other embodiments of the present invention; and

Fig. 11 is a partial sectional view illus trating one embodiment of the present invention wherein the percusson cap holder carries a movably mounted percussion cap,

Referring more particularly to Figure 1, A is a fuse body, shown in part, in a suitable cavity of which is located a fixed percussion cap B, firing being produced by the impact between this fixed percussion cap and a movable striker C. The retarding device comprises, according to the invention, a crown of balls D, normally wedged between the wall 6 of the enlarged space or chamber 1*] formed in the fuse body and a frusto conical bearing surface 0 formed upon the striker 0..

The strikeris arranged so as to be adapted to turn in the lodgment or enlarged space E under the action, for example, of the pressure of the air exerted upon an air screw F secured upon an extending portion C of the.

striker carrying rod. The halls B are normally pressed between the surfaces 0 and e, being held in place by the action of a spring G pressing at one end upon an interposed disc 9 and at the other upon a shoulder C of the striker C.

The forward movement of the striker towards the percussion cap can only take place under the action resultmg from a ro.--

tation and a push such as those which would be due to the movement of the projectile as it progresses in its flight in the air, and the forward movement of the striker will also result from the combined rotation and forward movement of the crown of balls D which take up, between the bearing surfaces 6, c a helical movement of small pitch.

It is possible by this means to retard the arrival of the striker, into a cocked pos1- tion. In" this first example the retarding device may be retained until the moment when the projectile has travelled over a suitable distance, the slow advance of the striker having then brought the balls D opposite a widened portion E of the lodgment E where these members cease to bear simultaneously upon the surface a and an adjacent complementary surface.

The striker Will then be definitely cocked, that is to say, ready to move so as to strike the percussion cap under the effect of an imact against an obstacle. The operation of the cocked striker maybe obtained by any known means. A pin H which, in the cooked position, is placed in the neighbourhood of the front face or edge A of the fuse body may, for example, be disposed upon the rod C As the result of an impact this pin will be immediately sheared through, thus allowing the striker to be driven towards the percussion cap-B.

With the retarding device described it is diflicult for untimely operations to take place, since the forward movement of the striker towards the percussion cap necessitates acombined push and rotation extending over a lengthy period. It will be immediately understood that a simple impact, in other words even a strong push, on condition however that it is not of such a nature as to cause the balls and their bearing surfaces to be crushed, will not allow sufficient advance of the striker to take place.

It is also easy to add to the retarding device described, additional safety devices which render an untimely operation impossible even in the event of the failure ofthe balls D.

Figui es 3 and 4 show in longitudinal sectional elevation an example in which the new retarding device is fitted to a percussion fuse for aerial bombs and is combined with a series of aditional safety devices.

In this example the balls D instead of being located between a frusto-conical wall formed upon the striker carrier C and the fuse body, are disposed between a similar frusto conical wall 0 and the cylindrical movable in the fuse body A. In this per- 7 cussion holder will be formed a flare or;

widened portion 71 in which the balls D must arrive for the striker to be cocked. The movable percussion'cap holder is normally prevented from entering into the fuse body by the pressure of a spring I one end of which presses upon the end of the fuse body. At the other end the percussion cap holder presses upon the plug A If the fuse was constructed as in the previous example, that is to say without additional external safety devices, in'other words if one imagines, in the drawing, that the retaining collar J, does not exist, an accidental push, even a very strong one, exerted upon the striker carrier C would not be sufficient to subject the balls D and their bearing surfaces to the action of an execessive force, since it would have the effect of driving in simultaneously the striker sand the percussion cap holder maintained in their relative positions by thewedging of the balls, and this driving in would be accompanied by the compression of the spring P. The inward movement of the striker carrier would in any case be limited by the boss of the air screw F abutting againstfthe front face or edge ofthe fuse body before any relative movement had taken place between the striker-carrier and the percussion cap holder. In other words any impact upon the projectile before the cooking of the mechanism produced by the combined rotation and'the pressure upon the striker carrier cannot produce an operation of the firing mechanism ancl cannot in addition give rise to an excessive force upon the. balls and their bearing surfaces.

In practice, in order to adapt the invention for use upon an aerial bomb, a safety device is interposed between the boss F of the air screw and the front face of the fuse body, which safety device is largely formed, in the known manner, for example by two half collars J which a spring tends to force open for their withdrawal, the two ends J of which collar are held together by a claw K which may be disengaged automatically by the fall of the bomb or by the action of a pull exerted by the pilot.

Once this safety device is withdrawn the pressure of the air acting upon the air screw exerts a push and produces at. the same time a movement of rotation of the latter the effect of which. is to produce an inward movement and a movement of rotation of the force exerted by the spring I is sufficient to overcome the push exerted by-the balls D upon the percussion cap holder, the latter remains fixed and the striker carrier advances relatively to the percussion cap holder. When the balls D reach the enlarged part i the pin H comes into contact with the front edge of the fuse body and the striker is cocked. Any impact against an obstacle after this will cause the pin H to be broken and the striker to be thrown.

percussion cap B, as shown in linear guiding of the striker carrier C obtained for example by means of a stud A attached to the plug A and engaging in a groove 0 upon the rod C it is possible to prevent any rotation of the striker from taking place until the latter, starting from the position shown in Figure 5, has travelled over the distance between the stud A and the transverse grohveC formed at the end of the said groove- 2' in the rod C and has reached the) position shown in Figure 6.'

As long as the groove C has not come into coincidence with the stud A the striker will not be able-to turn and it will carry along, through'themedium of the balls D the movable percussion cap holder I. As a consequence, the movement of rotation of the striker cannot take place, while the continuation of its inward movement is prevented by the end of the groove C abutting against the stud A. As the striker can no longer move forward, the pressure of the spring I combined with the rotation of the striker causes the percussion cap holder I to descend 5 in other words the percussion cap B and the point of the striker are made to move towards. each other.

As. soon as the balls vD coincide with the enlarged portion z" the spring I will be able to act freely and project the percussion cap B against the point of the striker, as shown in Figure 7.

By suitably adjusting the distance-to he travelled by the striker before-it can make.

its movement of rotation, the path to be travelled by the percussion cap holder before its enlarged portion 71 coincides with I the ballsD and by adjusting the tension ofthe compression spring I the period of flight of the projectile, at the, end of whichfiring will take place, may be determined...

Itis quite clear that modified means may be proirided for acting upon any one of the members which retard the operation of the firing mechanism; an action from the outside upon the spring I may be provided for, a device for varying the longitudinal stroke (without rotation) of the shaker may be provided or the duration of this travel of the striker may be varied by varying the mass or the shape of the air screw. A serles of different air screws which maybe fitted alternatively upon the striker carrier may also be provided. v a

Naturally the fuse described above, which is provided for time operation, may comprise, as it is known in principle, a device for making it operate by percussion when it strikes an obstacle; in the case when the time operation has not taken place before this impacts It will be suflicient, for ex'arnple, to provide for the possibility of shearing the stud or stop A by violently driving reached" the cocked position, the balls bein'g releasedfrom their support.

In the case of the application of the invention to vertically suspended aerial bombs, a suspension ring F may be provided, as

shown in Figs. 5 to 7, upon the boss of the air screw F or this ring may be mounted upon an extended portion of the striker carrier C In the examples described, the opposing spring I may bedispensed with if care is taken to make the movable percussion 'cap holder of suflicient mass. There is even an advantage, in certain cases, in, dispensing with this spring, in that it allows the striker and the percussion-cap holder to be brought nearer than when the bomb is in the. upturned position shown in the figures, which position it only takes up after a certain length of time from the moment when the projectile commences its fall.

The convergence between the bearingsurfaces of the balls D maybe obtained, as in the examples described above, by forming a rier and a cylindricalsurfaceupon the fuse body or upon a movable percussion cap holder. It 'may'on the other hand be 0bin the striker carrier which'has previously -frusto-co'nical surface upon the-striker cartained by forming the frusto-c'onicalsure face upon famovable percussion cap'holder,

the cylindrical bearing surface being formed upon the striker carrier.

Figure 8 shows in-s ectional elevation, such a modificationQ v In this case, as shown. in the figure, a

part C of the rod C of the striker carrier 'is turned down to a smaller diameter, which part replaces the widened portion '6 pro- 4 vided, in the prececling;,-examples in the movable' percussion cap holder. l ,v

In order to prevent an untimely impact exerting an excessive; force upon the balls D and their bearing surfaces, use may be made, instead of a movable percussion cap holder carried along longitudinally, of a fixed percussion cap combined with a striker carrier made in two parts. This modification is shown in longitudinal sectional elevation in Figure 9.

In this example the balls D are disposed between a frusto-conical bearing surface 6 formed in the lodgment E provided in the fuse body A and a cylindrical surface of the rod C of the striker carrier. The rod C comprises, as in the previous example, a turned down portion C". This striker carrying rod proper is adapted to move, by means of studs or pins C in slideways or slots 0 provided in the second member C of the rod which second member is provided externally with the air screw F. i

In the socket formed by the member C is disposed a spring C which constantly tends to maintain the striker carrier C in the position shown in the figure. It will be understood that once the expansible safety device J is disengaged a push withouta movement of rotation exerted upon the member C will only produce a movement of this member by the apertures c sliding over the pins C without displacing the striker carrier proper, C which will continue to be wedged or locked by the balls D.

An inward movement of the striker carrier C will only become possible under the eifect of the push exerted by the spring C combined with the rotation of the air screw F. As in the preceding examples the operation of the firing mechanism will only take lace at the end of a predetermined time, when the balls D coincide with the narrowed art C of the striker carrier C The latter will then be thrown'against the fixed percussion cap B by the expansion of the spring C.

Other safety devices of known type may be combined with the mechanical retarding device, acting by means of a crown of balls, which forms the essential feature of the invention.

In order to prevent any untimely pressure from being exerted, by hand, upon the air screw, projections f in the form of points may, as shown in Fig. 3, be provided upon the boss of the air screw; This will be sufiicient to prevent any pressure being exerted by hand upon the striker and consequently to prevent the enetration of the latter, for which penetration both of movement of rotation and a pressure are required. In other words if the air screw F is turned inadvertently by hand no inward movement of the striker will follow.

The mechanical retarding device, in all the forms of construction described, roduces a suitably slowed down advance 0 the striker towards the percussion cap by a sort of screwing motion of very small pitch. It

'yond the fuse body A.

is obvious that this mechanical retarding device may be employed in combination withthe usual screwing means by threaded screw and nut, the special slow action screwing motion retarding device which forms the subject of the invention then only entering into action after a first displacement of the striker resulting from the screwing" action obtained by means of a screw thread and nut has taken place.

Naturally, the rotating member upon,' which is formed one of the supports for. the balls of the retarding 'device, instead of being the striker carrier, as in the example described, may be a percussion cap holder,

provided with an air screw upon an externally extending portion, the said rotary percussion cap holder being combined, if desired, with a fixed striker or with a strlker only throw off the latter after the balls have reached an enlarged portion which causes them to be disengaged from their support, or after these balls have reached the end of the fuse body, which will only take place under the combined effect of the pressure of the spring and a rotation due to the action of the air upon the fins of the cover.

Figure 10 shows in sectional elevation v such a device.

' The spring K located in the cover L tends constantly to eject the latter, but it can only do this if, under the combined action of the pressure of the spring and the rotation of the cover resulting from the action of the air upon the fins L the balls have passed be- The invention may be employed in firing mechanisms for marine torpedoes, in hand grenades or the like and finally in all such mechanisms in which it is of interest to retard the operation of a firing mechanism, by subordinating the latter to a combined pressure and rotation produced over a sufficiently lengthy period.

Whatever be the screwing device for the striker carrier provided with an air screw, which is employed with the movable percussion cap 1, whether it is the ball device shown in Figs. 3 and 4 or other suitable device, the percussion cap instead ofbeing fixed in-the said movable percussion cap holder may itself be rendered movable in its lodgment, as shown in Fig. 11. In the 'lodgement I the percussion cap will normally be retained in its forward position by a spring I. In the event, of the striker being accidentally driven in and of the failure at the same time of the screwing device, the/forcing back of the percussion-cap into the lodgment' I by the point of the striker, will provide an additional safeguard.

What I claim is 1., A mechanical device for retarding. and preventing the operation of projectile fuses and for otheruses comprising a member to be displaced, a rotatable member, two convergent'bearing surfaces, one at least of said iearing surfaces being formedon said displaceable member, one at least of said bearing surfaces being formed on said rotatable member, a crown of balls placed between said convergent surfaces, one of' said sur faces having a transverse enlarged space at a point in its height, said balls being adapted to exert a wedging action and retain said displaceable member, and means for giving said crown of balls a combined movement of ro-' tati'on and advance between said bearing surfaces causing said displaceable member and said balls to advance in a helical movgment of very small pitch, said wedging action being removed when said balls enter said en larged space and escape from between said convergent surfaces.

2. In a device of the class cussion cap holder, and a striker, said two elements being provided with converging.

bearing surfaces and one of said surfaces being cut away to 'form an enlarged space, a crown of balls having engagement with said converging surfaces, and means for giving said crown of balls a combined movement of rotation and advance longitudinally of said elements between said bearing surfaces to move said balls into said enlarged space.

3. In a device of the class described, two elements adapted for relative longitudinal movement, one of which supports a percussion cap, said elements being provided with converging bearing surfaces, one of the latter being cut away to form an enlarged space, a crown of balls having engagement. w1t'l1 sald converging surfaces to prevent Sald' relative movement of said elements, and means for imparting a combined movement of rotation and advance to said balls to move the same into said enlarged space, whereby said two first named elements are adapted for said relative movement.

4. In a device of the class described, two

- elements adapted for relative longitudinal movement, one of which constitutes a per- 4 cussion cap holder, said elements having converging surfaces, one of the latter being cut away to form an enlarged space, a crown of balls having engagement with said converging surfaces for locking said elements against said relative movement, and an air screw for moving said balls into said enlarged space whereby said balls are moved out of locking engagement with said surfaces described, a perand said elements are adapted for relative movement.

5. In a device of the class described, a member adapted to be longitudinally displaced, a rotatable member, said members having converging bearing surfaces, a crown of balls placed between said converging surfaces for normally preventing longitudinal movement of said displaceable member, and means for giving said crown of balls a combined movement of rotation and longitudinal advance between said bearing surfaces longitudinally in said direction to free the same from locking engagement with said first named means.

7. A retarding device for fuses comprising, in combination with a projectile body, a member carried by said body, a device adapted to 'coact with said member and adapted for longitudinal movement relative thereto, means normally locking said device against longitudinal movement relative to said member, and means for rotating said device and simultaneously moving the same longitudinally to free the latter from looking engagement with said first named means.

8, A retarding device for fuses comprising, in combination with a projectile body, a percussion cap holder in saidbody, a per cussion cap carried by said holder, a striker adapted for longitudinal movement relative to said percussion cap, saidv holder and striker being provided with converging surfaces, a crown of balls engaging said surfaces, and an air propeller for rotating said crown of balls and simultaneously moving the same longitudinally.

9. A device of the class described comprising, in combination with a projectile body,

a holder movably mounted in said body, a percussion cap carried by said holder, striker means amociated with said holder, said striker and holder having converg ing',sur-

faces, one'of said surfaces being cut away to form a lodgment, a striker extendzng into said holder, means engaging said converging surfaces for preventing relative longitudinal movement between'said striker and percussion cap, and means for moving said first named means into said lodgment;

10. A device of the class described comprising, in combination with a projectile body, a holder movably mounted in said body, a percussion cap carried by said holder, striker means associated with said holder, said striker and holder having converging surfaces, one of said surfaces being cut away to form a lodgment, a striker extending into said holder, means engaging said converging surfaces for preventing relative longitudinal movement between said striker and percussion cap, means for moving said first named means into said lodgment, and pin and slot means operatively connecting said holder and fuse body. X

11. A device of the 'class described comprising, in combination with a projectile body, a holder movably mounted in said body, a percussion cap said striker and holder having converging surfaces, one of said surfaces belng cut away to form a lodgment, a striker extending into said holder, means engaging said con-verging surfaces for preventing relative longitudinal movement between said striker and percussion cap, means for moving said first named means into Y said lodgment, and resilient means for resisting movement of the holder relative to the projectile body.

In testimony whereof I have signed this specification.

LEON EMILE REMONDY.

carried by saidholder, striker means associated with sa1d-ho1der,. 

